The 36-year-old Haas converted three of his seven break points to beat the Italian in under two hours. He will face Slovakian qualifier Martin Klizan, who defeated Denis Istomin 7-6(3) 1-6 6-1 in their quarter-final.

Haas, who defeated fellow German Philipp Kohlschreiber in the final last year, is making his comeback from a right shoulder injury.

Top seed Fabio Fognini eased into the final four with a 6-2 6-2 win over Brazilian qualifier Thomaz Bellucci. The Italian will next face the winner of the quarter-final between 'lucky loser' Ricardas Berankis and German qualifier Jan Lennard-Struff.